Electrolyzing apparatus.



E. L. THORP. ELBGTROLYZING APPARATUS. APPLICATION FILED NOV. 21, 1905..

930,902. me11A-dy Aug. 1o, 1909.

- electrode plate, and wliiclnbeconiing ab-v certain nevt and usefulImprovements vin and iiat. )late :ir sheet. To this'end the o) iositcfaces are exposed on one side to .forni active 4as its mechanicalstrength is scarcely called UNITED ls. raTns PATENT OFFICE.

EDGAR LESLIE THOP, 0F NQTTINGHAM, ENGLAN D, ASSIGNOR T() THEBRITISHHOSIERY &

ELiio'rnoLYTic ,BLD y.Giulia .O

, LD.; or. LoNnoN, ENGLAND.

maoraetrzrus APPARATUS.

l V Speeitte,tion of Letters Patent.

lPatented aug. 10, 1.909.

Application tiled November gli, 1905. Serial No. 288,475.

To all whom 'it may concern: y l Be it known that I5 EDGAR LESLIETrione, a subject of the King of Great Britainp rc.; siding at 44Parliament street Nottingham, England, electrical engineer, haveiurentfd Relating to Electrolyzing Apparatus, of which the-followingis aspecification.

This invention relates to improvements in electrodes for electrolyzingapparatus, such for instance as' used for electrolyzing brinel solutionsto produce bleaching liquors,l and has reference more particularly tothe electrodes whereby the decomposition of the solution is effected. it The invention is designed to enable thin sheets 'or plates, say ofplatinum or platinoiridium, to be used 'very economically as theelectrodes, while guarding against disintegration thereof. It issupposed that this disintegration is due to the molecular reaction setup Within the metal by the differentl occluded gases (usually. with abrine solution.. hydrogen and chloe-ii) liberated at opposite sides orfaces of the saine sheet or sorbed or ocehided in the metal, ieactfwitheach other'iiiside the'metal-itself. -Now actor-ding to the presentinventiomineans are provided 'lor preventing any particular parto't' theelectrode t'roni having dili'erentz gases liberated on oppositesidcsthcreof, and this is etl'ectedwithont rendering any considerableportion of the metal inert and without altering' its formmaterially,from that oil a .surfaces of the plate may be divided up intosections, say by means of a suitable protective and insulatingYmaterial, such as glass or slate, or in some, `ases Celluloid, in such`a manner that the portions ot' -metal.^\\'l iose sections are distincty:,troin` those `portions. which forni the Vactiije sections on the otherside, while the insulating covbrings or strips serve also as supports tostiifeii or strengthenthe sheet or plate, and alternate with leach otheron oppositesides.` .The metal-sheet or' electrode proper can thus bemade very thin,

into play, and the arrangement is a very economical one sincepractically the whole oi the platinum sheet is in operation with thepossible exception ot' the narrow noni active intervening` bands orsections hereinafter mentioned. it will thus be seen that ,if theIactive sections on one. side of the plate should become charged orpermeated with .occlnded hydrogen, there is no chance ot' such occludedhydrogen setting up reactions or molecular etl'ects inside the platewith the chlorin produced or liberated on the opposite Side, and hencedisintegration of the plate from this canse is entirely prevented. whilea` very sitinple and durable construction oit electrode is attained.

ln ord-er that the invention may be more readily understood. referencewill now be had to the annexed drawings in which lfignxe l is a sectionot an electrolytic cell of a type with which the improved'electrodes maybe adrantageolisly employed. Fig. l is a plan showing a modifiedarrangement thereof. Fig. 2 is a vertical section showingoneconstruction ot' electrode havinga flat sheet with the activesections all in the same plane, the thickness being exaggerated tomal-:es the figure clear. Fig. 2l is a trout elc- \ation of the electrode shown in Fig. 2. Fig. 4 is a cross section illustrating a modi`tit-ation ot thc electrode shown in Fig. 2 and indicating how the activesections may have slight shoulders or olf-sets between them. Fig. 5 isan elevation showing another forni or mmlitication.v i

a is the electrolw/.ertrough or cell proper; A arethe two main positivand negative plates or poles and raiethc intermediate i lelectrodesdividing the elcctrolyzer into conipartincnts which in etl'ect aredistinct cells. .These cells may be arranged so that the solutioncanflow 'lroni one to the other as showniby the arrows in Fig. l, or sothatit can flow sidewisc through each cell indepe'i'idently as shown bythe arrows in Fig. 1. On applying to the terminal electrodes/1 aditlerence of potential of say 20() volts,`the`re will he set up in eachcompartment or cell Z a diti'erence of say 5 to 7 volts more or less,`

'accordingly-to the number of cells, andthe liquid will be-siibicctcd todecomposition as it flows through 'each disengaging say chlorin on oneside andsa'y hydrogen on the other side ol' each electrode. In'Fig. 1the liquid enters at c andilows away at u after passing alternately upand down over and under the electrodes. In Fig. 1a however, the liquidis fed into a side compartment fr and flows across to' an outletcompartment an1 through suitable apertures a in the longitudinalwalls,i-f. The electrodes c are iXed between these walls a and every third orfourth one c is arranged to Jform a division plate so to separate theapparatus into sections, and to act as a partition or Walla'l to divideoii' the spaces or cells d. g

Referring to Figs. 2 and 3, it will be clear hoW the platinum orplatino-iridium conducting plate or sheet c which forms the body of theelectrode, is flat and is provided with transverse strips of glass,varnish, or other suitable insulator e cemented thereto at suitabledistances apart so that the`int'ervening exposed active sections orparts on one side alternate with the sections on the other side. Theedges of the strips e on opposite sides overlap somewhat, leavingbetween them a narrow neutral or non-active band or section of metal gcovered on both sides with insulating material, thus better insuring theseparation of the dilferent active sections f f. Thus the electrode asshown consists of an active section f exposed on one side; then abovethis-a very narrow v non-active band or intervening section g covered onboth sides by the overlapping edges of the insulator e, then anotheractive section f exposed on the opposite side, and

so on. Owing to the plate or sheet being used in a Hat form itisutilized rvery economically and the portions thereotl (g) which areinactive are reduced to an absolute minimum. In this way the metal form`ing the section f which is exposed say to .ferredto are obviated.

chlorin on one side of the plate is kept distinct from that of thesection f which is exposed to say hydrogen on the opposite. side,although it 1s very closely connected therewith, both electrically andintegrally, and thus molecular actions ot the kind re- Care must betaken that the currents are not stronger thanthe neutral interveningbands or Istrips g can transmit withoutheating. Obviously these neutralbands g` may be bent sidewise some# what, as in Fig. 4, and strips e maythen lie flush' in the bends, hollows or sections, Whereas in Fig.2,'the adjacent strips e project more or less ,from the plate onopposite 1 sides. In lthelatter case, they havel the advantage ofserving toprotect the plate from accidental damage `by contact with' anycleaning instruments inserted into the cel In either case, however, theexposed sections lie substantially in or very near the same plane andthe plate or sheet is provided with extended flat faces thus as statedreducing the extentof the neutral portions g and' so using the platinumin the most eco-I nomical manner.

' Instead of being merely divided into lon` lgitudinal sections, theraces of the plate may be divided up in dili'erent ways, say checkerwiseinto squares as in Fig. 5, which alternate with ca ch other on oppositesides in the lnanner above referred to. Moreover Vinstead of usinginsulating strips, an insulatinggrid may be employed, ont-he plates maysimply be coated with a suitable var- Afnish at the parts required.According to a t'urther modification the platinum sheet may bccorrugated to increase the active surface and the strips may besimilarly corrugated .to correspond thereto if desired. The protectiveinsulating material by which the faces of the plate are thus divided maybe arranged also to serve as a strengthening frame or support,. andsuitable distance pieces or Iseparators may be arranged bctween theplates, preferably resting at their points of contact only against suchinsulating material thereby preventing the Vcovering up, of any parts ofthe active sections. Convenient arrangements may also be provided toenable any individual plate to be removed if desired.

What I claim and desire to secure by Letters Patent of the United Statesis 1...An electrode formed of a plate or sheet having active sections onone side thereof alternating with active sections lon the other side, acovering of insulating material applied over each of the unexposed sides of the sections, the edges of said coverings on opposite sides ofthe sheet overlapping slightly and forming narrow neutral strips coveredon both sides, substantially .as and for the purpose set forth.

2. An electrode having alternating exposed or active strips or sectionson op osite sides, such sections lying substantial y in thesame verticalplane in order to reduce the extent of the neutral intervening portions,and having inactive or covered vertical strips between said activestrips, and a thin insulating covering for the inactive strips, suchcovering being wider than the active strips, so 4asto form narrowneutral strips covered on both sides, substantially as described.

In testimony whereof I have hereunto set my hand in presence of twosubscribing Ewitnesses this 4th day of November 1905.

EDGAR LESLIE THOR?.

Witnesses:

ERNALD SIMPSON MosELEY, MALCOLM SME'rnURsr.

